It sounds like your friends really care about you . The potluck thing is great because you can pick and choose. As far as amounts, I just imagine a set of measureing cups and the amount of food it would take to fill the different sizes. You should be able to identify the main ingredients, and unless there are a lot of hidden carbs, don't worry about cals and fat.

The hospital stay could be tricky. Someone posted a few weeks ago that their "diabetic diet" while in the hospital was high in carbs. Is it possible to get a copy of menus b4 you get there to give you a chance to decide if you want "diabetic", or "regular" and choose the best for you from that. My experience with hospitals is that you have some control on food choices. Good luck.